Observers of the bizarre 2016 Republican presidential contest may have thought that the weekend's sudden announcement that Ted Cruz and John Kasich would team up to stop Donald Trump was about as desperate a ploy as we might expect to see. After the New York primary, after all, Cruz joined Kasich in being mathematically blocked from winning a majority of pledged delegates, meaning that the only hope each has to be the party's nominee is to also keep Trump from getting to that mark.

That effort collapsed faster than you could say, "who's partnering with what, now?" And to add another layer of insult, Trump demolished his two competitors in Tuesday's primaries, making his push for 1,237 delegates that much easier. Desperate ploy, seemingly foiled.

But Cruz appears to have another ploy ready to go. As our Robert Costa reports, Cruz will grab a few headlines by preemptively naming his one-time competitor Carly Fiorina as his running mate. This carries only slightly more weight at the moment than if Martin O'Malley were to appoint a secretary of defense, but Cruz isn't doing it for the purposes of ensuring that he's got a strong successor on the long-shot chance that he dies after his long-shot chance at the presidency comes true. The move is blatantly and obviously political -- an attempt to toss one last roadblock in Trump's path before voting ends in the primaries -- with one of the last states to vote being Fiorina's delegate-rich home state of California.

It's nearly as transparent a sop to the state as was his little performance about the "basketball ring" in Indiana. He couldn't name Ronald Reagan or In-N-Out as a running mate, so why not a California woman?

Here's a quick review of how the delegate math in the state works: The winner of California's primary will get 13 statewide delegates, and the winner of each of the 53 congressional districts will get three apiece. This is the sort of system under which Trump has made huge gains in his totals over the course of the campaign, leveraging big wins in South Carolina and New York to pull in nearly all of the delegates in each. Trump's seen a recent spike in his lead statewide, and a recent survey suggested that he held a lead in every region of the state.

The Fix's Peter W. Stevenson breaks down the remaining states on the GOP primary schedule, and why California and Indiana are the most important states left. (Peter Stevenson/The Washington Post)

For Cruz to win at the convention, he needs Trump not to. And for Trump not to, Cruz needs Trump to not win most of the delegates in California. And for that to happen, Cruz needs to shift the vote. Hence Fiorina.

Why Fiorina? A few reasons.

First, she's a woman. As we've pointed out, Trump does much worse with women (even Republican women) than he does men. In Fox News's most recent poll in the state, though, Trump still leads with women -- just by less. He's up 27 points over Cruz overall, but up 32 with men and only 22 with women. If Cruz can peel away more of that vote, it's to his advantage.

Second, she'll likely to appeal to voters in places in California that Cruz doesn't. Fiorina was once the chief executive of Hewlett-Packard, one of the founding giant firms of Silicon Valley. She has an appeal to the technocratic, more moderate side of the Republican Party that Cruz lacks, and which at this point seems to lean more toward Kasich than Cruz. (The Capitol Weekly poll linked above had Trump at 39 percent in the Bay Area to Kasich's 25 and Cruz's 23.) Those Bay Area districts are also more heavily Democratic, meaning that it will take fewer votes to win than in other parts of the state. This strategy helped Trump sweep delegates in dark-blue parts of New York state; in California, it will allow Fiorina to blanket her home turf to help Cruz peel those delegates away.

Third, she's not unpopular among Republicans. Granted, we don't have recent numbers on Fiorina's favorability (since she was always a long-shot in the 2016 race and polling costs money), but a December Quinnipiac poll had her at plus-35 net favorability nationally. More than half of Republicans viewed her positively and under one-fifth negatively. By contrast, Cruz's most recent net favorability rating, from a Suffolk University poll, had him at plus-15 with Republicans. Sure, she's not as popular nationally, but neither are the likely nominees for each party.

And besides, Cruz's goal isn't to spend the next four years working with Fiorina; his goal is to keep the door of possibility open that he might get to spend the next four years doing that. To that end, he needs to stand in Trump's way in California, but so far hasn't had much luck in doing so. So he grabbed the closest Californian.

Trump, we will note, seems ready.

Ted Cruz exits the presidential race

Republican presidential candidate, Sen. Ted Cruz, R-Texas, speaks with his wife, Heidi, by his side during a primary night campaign event, Tuesday, May 3, 2016, in Indianapolis. Cruz ended his presidential campaign, eliminating the biggest impediment to Donald Trump's march to the Republican nomination. (AP Photo/Darron Cummings)